The Battle of Lang Vei was a battle of the Vietnam War fought on the night of 6 February 1968, between elements of the People's Army of Vietnam (PAVN) and the United States-led Detachment A-101, 5th Special Forces Group.
Lang Vei was an American Special Forces camp, located approximately 7 km (4.5 mi) west of the Khe Sanh Combat Base in Quang Tri Province, in the northwestern corner of the Republic of Vietnam (RVN or South Vietnam), near its borders with the DRV and the Kingdom of Laos. The camp was constructed in 1967 for operations of the Civilian Irregular Defense Groups (CIDG) along the Laotian frontier. It was overwhelmed by North Vietnamese forces on 7 February 1968. The history of the camp and the battle for the camp are also described in some detail in the article on the Battle of Khe Sanh.
Lang Vei was positioned some nine kilometers (5.5 mi) west of Khe Sanh village on Route Coloniale 9. Known to Americans as Highway 9, this major roadway stretched through Quang Tri Province from Dong Ha on the coast west to Lao Bao, Laos, passing through places such as Cam Lo as well as Khe Sanh. Lang Vei was defended by a force of 500 CIDG Montagnards and 24 U.S. Special Forces personnel.